[RFC][PATCH 0/2] Make radeonfb use PCI PM core for suspendig device (was: Re: [RFC][PATCH] PCI PM: Be extra careful when changing power states of devices)

From: "Rafael J. Wysocki" <rjw@sisk.pl>
To: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Linux PCI <linux-pci@vger.kernel.org>,
	pm list <linux-pm@lists.linux-foundation.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Andrew Morton <akpm@linux-foundation.org>
Subject: [RFC][PATCH 0/2] Make radeonfb use PCI PM core for suspendig device (was: Re: [RFC][PATCH] PCI PM: Be extra careful when changing power states of devices)
Date: Sun, 22 Mar 2009 22:08:21 +0100	[thread overview]
Message-ID: <200903222208.22434.rjw@sisk.pl> (raw)
In-Reply-To: <200903210003.55161.rjw@sisk.pl>

On Saturday 21 March 2009, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rjw@sisk.pl>
> 
> The story in http://bugzilla.kernel.org/show_bug.cgi?id=12846 shows
> that setting the power state of a PCI device by
> pci_raw_set_power_state() may sometimes fail.  For this reason,
> pci_raw_set_power_state() should not assume that the power state of
> the device has actually changed after writing into its PMCSR.
> Instead, it should read the value from there and use it to update
> dev->current_state.  It also is useful to print a warning if the
> device's power state hasn't changed as expected.
> 
> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
> ---
OK, since the Ben's radeonfb fix for bug #12846 has been merged, I'd like
to do something a bit different.

Patch 1/2 introduces __pci_set_power_state() that will allow the radeonfb
driver not to open code PCI PM operations.

Patch 2/2 makes the driver use __pci_set_power_state().

Comments welcome.

Thanks,
Rafael